Antenna equipment and artificial satellites

Abstract

To suppress the occurrence of twisting when an antenna device is deployed from a stored state to a deployed state. [Solution] The antenna device (1) can be in a stored state stored in a housing (10) and in a deployed state extending from the housing to the outside. It comprises an extension shaft member (20) that can be extended in the axial direction from within the housing, a plurality of element holders (30) that can move along the extension shaft member, and an antenna element (40) that can be deployed from the element holder. In the stored state, the antenna element is wound around the axis of the extension shaft member on each of the element holders, and the direction in which the antenna element is wound around some of the plurality of element holders is opposite to the direction in which the antenna element is wound around the remainder of the plurality of element holders.

Description

[Technical Field]

[0001] The present invention relates to an antenna device and an artificial satellite. [Background technology]

[0002] Artificial satellites are equipped with antenna devices for transmitting and receiving radio signals. A large antenna is required to transmit and receive low-frequency radio waves, including VHF and UHF, with high gain, but it must be miniaturized for installation on a launch vehicle. Therefore, there is a need to develop a deployable antenna that can be installed on a rocket in a compact, stowed state at launch and then deployed to the desired size in space.

[0003] As such an antenna device, for example, Patent Documents 1 and 2 disclose an antenna device that can be in a stored state where it is stored in a housing and in a deployed state where it extends outward from the housing, and that includes an extension shaft member that can be extended in the axial direction from within the housing, a plurality of element holders that can move along the extension shaft member, and antenna elements that can be deployed from the element holders. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7595992 specification [Patent Document 2] Patent No. 7651224 specification Summary of the Invention [Problem to be solved by the invention]

[0005] When deploying a deployable structure in space, depending on the behavior of the structure during deployment, increased friction in the moving parts can hinder the deployment process or cause the structure to twist. Furthermore, because there is no air resistance in space, any vibrations caused by twisting can take a very long time to resolve. In particular, twisting in a satellite antenna can lead to a risk of not being able to achieve the desired communication performance, and it is extremely difficult to repair an antenna on a satellite in space after the fact. Therefore, it is necessary to prevent twisting from occurring during the deployment process from the stowed state to the deployed state.

[0006] The present invention has been made in view of the above-mentioned problems, and has as its object to provide an antenna device and an artificial satellite that can suppress the occurrence of twisting during deployment from a stowed state to a deployed state. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided an antenna device that can assume a stored state in which it is stored within a housing and a deployed state in which it extends to the outside from the housing, the antenna device comprising: an extension shaft member that can extend axially from within the housing; a plurality of element holders that can move along the extension shaft member; and an antenna element that can be deployed from the element holder, wherein in the stored state the antenna element is wound around the axis of the extension shaft member on each of the element holders, and the direction in which the antenna element is wound around some of the plurality of element holders is opposite to the direction in which the antenna element is wound around the remainder of the plurality of element holders.

[0008] According to one aspect of the present invention, there is provided an antenna device that can assume a stored state in which it is stored within a housing and a deployed state in which it extends outward from the housing, the antenna device comprising: an elongated shaft member stored within the housing in a state in which it is axially retracted relative to an opening in the housing; a plurality of element holders stacked within the housing with an opening through which the elongated shaft member is inserted; and a deployable antenna element held by the element holders, wherein the antenna element is wound around the axis of the elongated shaft member on each of the element holders in the stored state, and the direction in which the antenna element is wound around some of the plurality of element holders is opposite to the direction in which the antenna element is wound around the remainder of the plurality of element holders.

[0009] According to one aspect of the present invention, the directions in which the antenna elements are wound around two adjacent element holders are opposite to each other.

[0010] According to one aspect of the present invention, the direction in which the antenna element is wound around the even-numbered element holders from the base end side of the extension shaft member among the multiple element holders is opposite to the direction in which the antenna element is wound around the odd-numbered element holders.

[0011] According to one aspect of the present invention, the antenna element is formed from a convex tape and is wound around the element holder so that the convex surface of the convex tape faces outward in the stored state.

[0012] According to one aspect of the present invention, the direction in which the antenna elements are wound around each element holder is set so that the difference between the total strain energy stored in the antenna elements wound in one direction around some of the multiple element holders in the stored state and the total strain energy stored in the antenna elements wound in the other direction around the remaining parts of the multiple element holders is minimized.

[0013] According to one aspect of the present invention, four antenna elements are connected to each element holder so that the antenna elements extend in a cross shape in the deployed state.

[0014] According to one aspect of the present invention, there is provided a satellite including the antenna device described above. [Effects of the Invention]

[0015] According to the present invention, it is possible to suppress the occurrence of twisting when the antenna device is deployed from the stored state to the deployed state. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view showing the appearance of an antenna device in a deployed state according to an embodiment of the present invention. [Figure 2] 1 is an enlarged perspective view of an antenna device in a deployed state according to an embodiment of the present invention; [Figure 3] 1 is a perspective view showing the appearance of an antenna device in a stored state according to an embodiment of the present invention; [Figure 4] 1 is a perspective view showing the internal configuration of an antenna device in a stored state according to an embodiment of the present invention; [Figure 5] 1 is a vertical cross-sectional view showing the internal configuration of an antenna device in a stored state according to an embodiment of the present invention. [Figure 6] 1 is a schematic diagram showing storage sections for various components within an antenna device in a stored state according to an embodiment of the present invention; [Figure 7] FIG. 3 is a perspective view showing a surface of an element holder. [Figure 8] FIG. 4 is a perspective view showing the back surface of the element holder. [Figure 9] FIG. 4 is a perspective view showing a plurality of element holders in a stored state. [Figure 10] FIG. 4 is an enlarged vertical cross-sectional view of the element holder in a housed state. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of an antenna device and an artificial satellite according to the present invention will be described in detail below with reference to the drawings. Note that in the following description, the terms "up" and "down" and other terms relating to the up and down directions are used for convenience of explanation, and the antenna device may be in any position.

[0018] Fig. 1 is a perspective view showing the appearance of an antenna device in a deployed state according to an embodiment of the present invention, and Fig. 2 is an enlarged perspective view of an antenna device in a deployed state according to an embodiment of the present invention. Fig. 3 is a perspective view showing the appearance of an antenna device in a stored state according to one embodiment of the present invention. Fig. 4 is a perspective view showing the internal configuration of an antenna device in a stored state according to one embodiment of the present invention. Fig. 5 is a vertical cross-sectional view showing the internal configuration of an antenna device in a stored state according to one embodiment of the present invention. Fig. 6 is a schematic view showing storage sections for each component within an antenna device in a stored state according to one embodiment of the present invention.

[0019] The antenna device 1 of this embodiment is a device that is incorporated into an artificial satellite and is used to transmit and receive radio waves. The antenna device 1 can be in a retracted state where the antenna is housed within a housing 10, and in an extended state where the antenna is extended from the housing 10.

[0020] As shown in FIGS. 1 and 2, the antenna device 1 includes a housing 10, an elongated shaft member 20, a plurality of element holders 30, antenna elements 40 connected to the element holders 30, and a holding member 50.

[0021] As shown in FIG. 3, the housing 10 comprises a housing body 11 and an opening / closing lid 12 connected to the housing body 11. The housing body 11 is a rectangular parallelepiped with one side open. The opening / closing lid 12 is rotatably attached to the edge of the opening of the housing body 11 with a hinge 15 as the rotation axis. This allows the opening / closing lid 12 to be in a state where the opening of the housing body 11 is closed and a state where the opening of the housing body 11 is open. In the stored state, the opening / closing lid 12 closes the opening of the housing body 11, and in the unfolded state, the opening / closing lid 12 opens the opening of the housing body 11. The hinge 15 is spring-loaded and biases the opening / closing lid 12 to open.

[0022] As shown in FIGS. 1 and 2, in the unfolded state, the extension shaft member 20 extends linearly from within the housing 10. Hereinafter, the extension direction of the extension shaft member 20 will be referred to as the "axial direction," and the line through which the extension shaft member 20 extends in the axial direction will be referred to as the "axis line" of the extension shaft member 20. Furthermore, the direction through the extension shaft member 20 in a plane perpendicular to the axial direction of the extension shaft member 20 will be referred to as the "radial direction." The extension shaft member 20 is formed from a pair of metal convex tapes 20A. The convex tape 20A is a thin, plate-like member that extends linearly and has an arc-shaped cross section. When the fixing force is released from the rolled-up state, a restoring force acts on the convex tape 20A, causing it to return to a linear shape. In this embodiment, the extension shaft member 20 is configured by overlapping the pair of convex tapes 20A so that the concave sides of the convex tapes 20A face each other, and connecting both side edges.

[0023] The multiple element holders 30 are arranged along the elongated shaft member 20 at predetermined intervals set by design when in the expanded state. In the expanded state, the element holders 30 are held in position by the holding member 50, but are movable along the elongated shaft member 20 during transition from the contracted state to the expanded state. In this embodiment, four element holders 30 are arranged along the elongated shaft member 20. The element holders 30 are, for example, plate-shaped members made of resin. The fourth element holder 30, which is the fourth element holder 30 from the housing 10 (the most distal end of the elongated shaft member 20), is fixed to the distal end of the elongated shaft member 20. In addition, the first to third element holders 30, which are the first to third element holders from the housing 10, have openings 304 ( FIG. 7 ) formed in their centers, through which the elongated shaft member 20 can be inserted. The elongated shaft member 20 is inserted through the openings 304 of the element holders 30.

[0024] In the unfolded state, the antenna elements 40 each extend linearly outward from the element holder 30 perpendicular to the axial direction of the extension shaft member 20. Each antenna element 40 is formed from a single piece of metal convex tape. Four antenna elements 40 are connected to each element holder 30. In the unfolded state, the four antenna elements 40 connected to each element holder 30 are arranged at equal angular intervals (90°) and extend perpendicular to the axial direction. In other words, the antenna elements 40 extend in a cross shape in a plane perpendicular to the axial direction.

[0025] The holding member 50 is made of a flexible wire such as a string, and is fixed to each element holder 30. The attachment positions of each element holder 30 to the holding member 50 are set at predetermined intervals. In addition, the ends of the holding member 50 are fixed to the bottom of the element storage section 10A in the housing 10. This ensures that the spacing between the element holders 30 is maintained at a predetermined interval when the extension shaft member 20 transforms from the stored state to the deployed state. Here, "predetermined spacing" does not mean equal spacing, but rather spacing that is preset in the design. The spacing and length of the antenna elements 40 affect the performance gain (antenna communication efficiency) and reception frequency, and are therefore designed to achieve the desired frequency and communication efficiency. In this embodiment, the attachment positions of the element holders 30 on the holding member 50 are adjusted so that, when the string constituting the holding member 50 is tensioned, the distance between the first element holder 30 and the second element holder 30, the distance between the second element holder 30 and the third element holder 30, and the distance between the third element holder 30 and the fourth element holder 30 are each set to a predetermined distance. Furthermore, a portion of the extension shaft member 20 is held without stretching within the extension shaft member storage section 10B, maintaining a stretching force that stretches it in the axial direction. This keeps the string constituting the holding member 50 in a tensioned state, preventing it from sagging due to the stretching force, and enabling the set predetermined distance to be stably maintained. While an antenna formed solely by the free length of a spring can change its overall length due to disturbances such as satellite movement, this configuration is resistant to such disturbances. Therefore, the distances between the portions of the holding member 50 where adjacent element holders 30 are fixed are each set to a predetermined distance. In this embodiment, four holding members 50 are provided, but the number is not limited to this, and it is sufficient to provide at least one. With this configuration, the antenna device 1 forms a cross Yagi antenna in the deployed state.

[0026] 2, an antenna feed board 60 is attached to the second element holder 30B, which is the second from the housing 10. One end of a feed cable 62 extending from inside the housing 10 is connected to the antenna feed board 60. The other end of the feed cable 62 extends to the outside of the antenna device 1 and is electrically connected to another base of the satellite, and an electrical signal is supplied to the antenna feed board 60 via the feed cable 62.

[0027] The feeder cable 62 extends from inside the housing 10 to the second element holder 30B along the extension shaft member 20. As a result, the antenna element 40 connected to the first element holder 30A, which is the first from the housing 10, functions as a reflector, the antenna element 40 connected to the second element holder 30B, which is the second from the housing 10, functions as a radiator, and the antenna elements 40 connected to the third and fourth element holders 30C, 30D, which are the third and fourth from the housing 10, function as directors.

[0028] In this embodiment, four element holders 30 are provided, but the third and fourth element holders 30C and 30D can be omitted, and five or more element holders 30 can be provided.If multiple element holders 30 to which antenna elements 40 are connected are provided, the device can function as an antenna device.

[0029] 4 to 6, an element storage section 10A, an extension shaft member storage section 10B, a power supply cable storage section 10C, and an opening mechanism storage section 10D are formed inside the housing 10. The element storage section 10A is a space that opens upward, and in the stored state, the upper opening is closed by an opening / closing lid 12. In addition, a spring 13 (FIG. 2) is attached to the bottom of the element storage section 10A.

[0030] The elongated shaft member storage section 10B is disposed below the element storage section 10A. An opening is formed between the element storage section 10A and the elongated shaft member storage section 10B to connect these spaces, and the elongated shaft member 20 stored in the elongated shaft member storage section 10B advances into the element storage section 10A through this opening.

[0031] The stretching shaft member storage section 10B is provided with a stretching shaft member storage device 18. The stretching shaft member storage device 18 is a device that winds up and stores a stretching shaft member 20. The stretching shaft member storage device 18 has a rotatable shaft portion 18A, and one end of the stretching shaft member 20 is connected to a connecting member 18B fixed to the shaft portion 18A. In the stored state, the stretching shaft member 20 is stored in the housing 10 in a state where it is wound around the shaft portion 18A. Furthermore, the stretching shaft member storage device 18 is configured to restrict rotation of the shaft portion 18A when the opening / closing lid is closed.

[0032] The power feed cable storage section 10C is disposed below the element storage section 10A and to the side of the extension shaft member storage section 10B. An opening is formed between the power feed cable storage section 10C and the element storage section 10A to connect these spaces, and the power feed cable 62 enters the element storage section 10A through this opening.

[0033] 4, the antenna device 1 also includes an opening section 14 for opening the opening-closing cover 12, and an opening section drive board 16 for driving the opening section 14. The opening section 14 is housed in the opening mechanism housing section 10D. In the housed state, the opening section 14 holds the opening-closing cover 12 in a closed state, and when the opening section drive board 16 drives the opening section 14, the opening section 14 releases the opening-closing cover 12, allowing the opening-closing cover 12 to rotate.

[0034] 6, in the antenna device 1 of this embodiment, an element storage section 10A is arranged on the upper hinge 15 (rotation axis) side within the housing 10, and an extension shaft member storage section 10B is arranged on the lower hinge side. As a result, a central axis CL2 (axis) of the extension shaft member 20 is positioned on the hinge 15 side with respect to a central axis CL1 in the width direction of the housing 10 (the left-right direction in FIG. 6). By shifting the central axis CL1 of the housing 10 and the central axis CL2 of the extension shaft member 20 in the horizontal direction in this way, it is possible to arrange an opening mechanism storage section 10D on the upper side of the housing 10 opposite the hinge 15, and to arrange a power feed cable storage section 10C on the lower side of the housing 10 opposite the hinge 15, thereby making effective use of the space within the housing 10.

[0035] Next, the basic configuration of the element holder 30 will be described. Fig. 7 is a perspective view showing the front surface of the element holder. Fig. 8 is a perspective view showing the back surface of the element holder. Note that the front surface of the element holder here refers to the surface on the tip side of the extension shaft member 20, and the back surface of the element holder refers to the surface on the housing 10 side. Figs. 7 and 8 show a second element holder. As shown in Figs. 7 and 8, the element holder 30 has a central frame portion 300 and protrusions 310 connected to each of the four sides of the frame portion 300. The protrusions 310 are formed near one end of each side of the frame portion 300.

[0036] The frame 300 is a square portion having a predetermined thickness. A flat plate 302 is provided inside the frame 300. An opening 304 is formed in the flat plate 302 of the element holder 30. The opening 304 has a shape that is line-symmetrical with one diagonal line as the axis of symmetry, and is a shape that combines two arcs. The shape of this opening 304 corresponds to the shape of the extension shaft member 20 formed by combining a pair of convex tapes. A closing plate 360 ​​(FIG. 8) that closes the opening 304 is attached to the tip side of the first element holder 30. The shape of the frame 300 is not limited to a square, and may be other polygonal, circular, elliptical, etc.

[0037] A front surface convex portion 314 having a substantially rectangular cross section is erected on the front surface of the protrusion 310. A front surface groove portion 312 having a substantially rectangular cross section is formed within the front surface convex portion 314. A rear surface recess portion 316 having a substantially rectangular shape is formed on the rear surface of the protrusion 310 at a location corresponding to the front surface groove portion 312. The shape of the inner surface of the rear surface recess portion 316 corresponds to the shape of the outer surface of the front surface convex portion 314. A through hole 318 is formed to connect the front surface groove portion 312 and the rear surface recess portion 316.

[0038] Although not shown in Figures 7 and 8, in the stored state, a lid member 340 (Figure 10) is attached to the bottom of the rear surface recess 316. The lid member 340 has a wide portion 342 and a narrow portion 344. The wide portion 344 is plate-shaped and its outer shape is approximately the same as the outer shape of the front surface protrusion 314. The narrow portion 344 protrudes from one side of the wide portion 342 and its outer shape is approximately the same as the inner shape of the front surface protrusion 314. The lid member 340 has two through holes 346, and the holding member 50 is fixed to the lid member 340 with the holding member 50 inserted through the through holes 346. The lid member 340 is fixed to the bottom of the rear surface recess 316 with screws or the like. As will be described later, when the element holders 30 are stacked in the stored state, the narrow width portion 344 of the cover member 340 fits into the surface groove portion 312 of the adjacent element holder 30, closing the surface groove portion 312.

[0039] The side surface of each protrusion 310 on the center side of the side of frame 300 is perpendicular to the radially outer surface of frame 300. The base end of antenna element 40 is fixed to the side surface of each protrusion 310. The radially outer surface of each protrusion 310 is formed in an arc shape.

[0040] Additionally, a first element guide 330 is attached to the surface of each protruding portion 310. The first element guide 330 is a plate material and protrudes radially outward from the protruding portion 310. In this embodiment, four first element guides 330 are attached to each element holder 30. The first element guides 330 are provided at positions that correspond to the corners of each side of the frame portion 300 so as to extend in the circumferential direction.

[0041] In addition, a second element guide 332 is attached to the back surface of the protruding portion 310. The second element guide 332 is a plate material and protrudes radially outward from the protruding portion 310. The thickness of the second element guide 332 is the same as that of the first element guide 330. In this embodiment, four second element guides 332 are attached to each element holder 30. The second element guides 332 are provided at positions corresponding to the centers of each side of the frame portion 300. The first element guide 330 and the second element guides 332 are shaped and arranged so that they do not overlap when viewed in the axial direction.

[0042] The first to fourth element holders do not need to have the same configuration. For example, the thickness of the flat plate 302 may be the same as the thickness of the frame portion 300. Also, a cylindrical guide portion that guides the extension shaft member 20 may be provided along the periphery of the opening 304.

[0043] The configuration of the antenna device in the retracted state will be described below. As shown in Figures 3 to 5, in the storage state, the opening / closing lid 12 is closed, and the top of the element storage section 10A is closed. The stretch shaft member 20 is stored in the stretch shaft member storage section 10B in a retracted (retracted) state, wrapped around the shaft portion 18A of the stretch shaft member storage device 18. The tip end of the stretch shaft member 20 advances into the element storage section 10A, and the tip end abuts the opening / closing lid 12. In this state, the shaft portion 18A of the stretch shaft member storage device 18 is restricted from rotating. Since the stretch shaft member 20 is formed by joining two convex tapes, a restoring force is generated in the stretch shaft member 20 by being wrapped flat around the shaft portion 18A of the stretch shaft member storage device 18, and a force is generated that causes the stretch shaft member 20 to advance upward from the stretch shaft member storage device 18.

[0044] In the stored state, the power feed cable 62 is spirally wound and stored in the power feed cable storage section 10C. The tip of the power feed cable 62 advances to the element storage section 10A, passes through the opening of the element holder 30, and reaches the power feed board 60 fixed to the second element holder 30.

[0045] FIG. 9 is a perspective view showing multiple element holders in a stored state. FIG. 10 is an enlarged vertical cross-sectional view of the element holder in the stored state. As shown in FIG. 9, multiple element holders 30 are stored in a stacked state within the element storage section 10A. As shown in FIG. 10, adjacent element holders 30 are stacked with the front surface convex portion 314 of one (lower) element holder 30 inserted into the rear surface concave portion 316 of the other (upper) element holder 30. As a result, a cover member 340 attached to the bottom of the rear surface concave portion 316 of the other element holder 30 closes the front surface groove portion 312 of the adjacent element holder 30. As a result, a storage section 350 for the holding member 50 is formed within the space surrounded by the front surface groove portion 312 and the cover member 340. Within the storage section 350, the portion of the holding member 50 located between the adjacent element holders 30 is stored in a spirally wound state, for example.

[0046] As described above, the first element guide 330 and the second element guide 332 are arranged so as not to interfere with each other. As a result, the second element guide 332 of one of the stacked adjacent element holders 30 is positioned between the first element guide 330 of the other element holder 30. As a result, the adjacent element holders 30 are stacked in closer proximity to each other.

[0047] The antenna elements 40 are held on the radially outer peripheral surface of the element holder 30 in a state where they are wound around the axis of the elongated shaft member 20. The antenna elements 40 are wound along the outer peripheral surface of the protrusion 310 of the element holder 30, thereby assuming a circular shape. Furthermore, the antenna elements 40 are guided by the first element guide 330 and the second element guide 332 so as to follow the outer peripheral surface of the element holder 30. Each antenna element 40 is held in a retracted state around the element holder 30 by abutting its tip against the inner wall of the element storage section 10A. The antenna elements 40 are made of convex tape and can be deployed outward from the element holder 30.

[0048] The direction in which the antenna element 40 is wound around some of the plurality of element holders 30A to 30D is opposite to the direction in which the antenna element 40 is wound around the remaining plurality of element holders 30A to 30D. As shown in Figures 4 and 9, in this embodiment, in the element holders 30B and 30D that are even-numbered (second and fourth) from the base end side of the elongated shaft member 20 among the plurality of element holders 30A to 30D, the direction in which the antenna element 40 is wound from the base end to the tip is clockwise when viewed in the axial direction from the tip side (top in Figures 4 and 9) of the elongated shaft member 20. On the other hand, in the element holders 30A and 30C that are odd-numbered (first and third) from the base end side of the elongated shaft member 20 among the plurality of element holders 30A to 30D, the direction in which the antenna element 40 is wound from the base end to the tip is counterclockwise toward the radially outward direction when viewed in the axial direction from the tip side (top in Figure 9) of the elongated shaft member 20. That is, the directions in which the antenna elements 40 are wound around two adjacent element holders 30 are opposite to each other.

[0049] In each of the plurality of element holders 30A to 30D, the antenna element 40 is wound around the element holder 30 so that the convex surface of the convex tape that constitutes the antenna element 40 faces outward in the stored state. When the antenna element 40 is wound in this manner so that the convex surface faces outward, strain energy in the stored state is smaller than when the antenna element 40 is wound inward, and therefore the moment acting on the element holder 30 when the antenna element 40 is deployed while rotating during deployment is smaller.

[0050] As described above, the direction in which antenna element 40 is wound around element holders 30B and 30D in the stored state is opposite to the direction in which antenna element 40 is wound around element holders 30A and 30C, so if antenna element 40 is wound around any element holder 30 so that the convex side of the convex tape faces outward, the direction in which the convex side of the convex tape constituting antenna element 40 faces will be opposite between element holders 30B and 30D and element holders 30A and 30C when unfolded. Even in this case, the effect on the return loss and frontal gain of antenna device 1 is minor compared to when the convex sides of the convex tape constituting antenna element 40 face the same direction when unfolded, and no problems will arise in communication performance.

[0051] Although four element holders 30 are provided in this embodiment, even if the number of the element holders 30 is other than four, the direction in which the antenna element 40 is wound around some of the element holders 30 can be set to be opposite to the direction in which the antenna element 40 is wound around the remaining element holders 30, as described above. In this case, as described above, the direction in which the antenna element 40 is wound around the even-numbered element holders 30 from the base end side of the elongated shaft member 20 can be set to be opposite to the direction in which the antenna element 40 is wound around the odd-numbered element holders 30. In other words, the directions in which the antenna element 40 is wound around two adjacent element holders 30 can be set to be opposite to each other.

[0052] Furthermore, as long as the direction in which the antenna element 40 is wound around each element holder 30 is set so that the difference between the total strain energy stored in the antenna element 40 wound in one direction around some of the multiple element holders 30 in the stored state and the total strain energy stored in the antenna element 40 wound in the other direction around the remaining parts of the multiple element holders 30 is minimized, the directions in which the antenna element 40 is wound around two adjacent element holders 30 do not necessarily have to be opposite to each other.

[0053] For example, when an antenna element 40 similar to that of the present embodiment described above is wound around each of the four element holders 30, the direction in which the antenna element 40 is wound around the first and fourth element holders 30A, 30D from the base end side of the elongated shaft member 20 may be opposite to the direction in which the antenna element 40 is wound around the second and third element holders 30B, 30C.

[0054] Furthermore, for example, if there are six element holders 30 and the length of the antenna element 40 wound around the first to third element holders 30 on the base end side of the elongated shaft member 20 is approximately twice the length of the antenna element 40 wound around the third to sixth element holders 30, the direction in which the antenna element 40 is wound around the first and third element holders 30 from the base end side of the elongated shaft member 20 may be opposite to the direction in which the antenna element 40 is wound around the second and fourth to sixth element holders 30.

[0055] In the stored state, the element holders 30 are stored in a stacked manner in the element storage section 10A. In this state, the element holders 30 are biased toward the opening by the springs 13 attached to the bottom of the element storage section 10A. In addition, a force is generated in the extension shaft member 20 that causes it to advance upward.

[0056] Next, the transition of the antenna device from the stored state to the deployed state will be described. When the antenna device 1 is transitioned to the deployed state, first, the satellite's control device sends a signal to the opening section drive board 16 instructing it to transition to the deployed state. When the opening section drive board 16 receives this signal, it drives the opening section 14, which then releases the closure of the opening / closing cover 12, making the opening / closing cover 12 rotatable. In conjunction with this, the locking member of the extension shaft member storage device 18 releases the restriction on the rotation of the shaft.

[0057] When the opening / closing lid 12 becomes rotatable, the opening / closing lid 12 opens due to a spring (not shown) provided on the hinge 15. At the same time, the extension shaft member 20 has a restoring force that tries to return it to a straight line as described above, and due to this restoring force, it extends outward from the housing 10, and the element holder 30 is released outward from the housing 10 by the restoring force of the extension shaft member 20 and the spring force of the assisting spring 13. As a result, the extension shaft member 20 advances outward from the housing 10, and the element holder 30 is released outward from the housing 10.

[0058] As the extension shaft member 20 extends, the first element holder 30 advances outward. Since each element holder 30 is fixed to the holding member 50, the element holder 30 is pulled by the holding member 50 and moves along the extension shaft member 20.

[0059] Then, extension of the extension shaft member 20 stops when the holding members between each element holder 30 and between the fourth element holder 30 and the housing 10 are in a tensioned state. With the holding members 50 in this tensioned state, the element holders 30 are positioned at a predetermined interval determined by the design.

[0060] Furthermore, as the element holders 30 are released from the element storage sections 10A, the constraint on the antenna elements 40 wound around the outer peripheral surfaces of the element holders 30 is released. When the constraint is released, the antenna elements 40 formed from the convex tape unfold while rotating in the direction opposite to the direction in which they were wound around the element holders 30 due to their own elasticity, and extend linearly outward from each element holder 30.

[0061] When this antenna element 40 is deployed, a moment is generated in each element holder 30 in the direction opposite to the direction in which the antenna element 40 rotates and deploys. However, in the stored state, the direction in which the antenna element 40 is wound around the even-numbered element holders 30B and 30D from the base end side of the elongated shaft member 20 is opposite to the direction in which the antenna element 40 is wound around the odd-numbered element holders 30A and 30C. Therefore, the direction of the moment acting on the even-numbered element holders 30B and 30D and the moment acting on the odd-numbered element holders 30A and 30C cancel each other out during deployment. Therefore, the moment around the axis of the entire elongated shaft member 20 is kept to zero or close to zero, and torsion of the entire elongated shaft member 20 is suppressed.

[0062] When the antenna device is deployed, the extension shaft member 20 extends linearly from within the housing 10. An excess length remains at the base end of the extension shaft member 20, and this excess length is wound around the shaft portion 18A of the extension shaft member storage device 18. As a result, a force acts on the extension shaft member 20 in the direction in which it advances. Furthermore, because a force acts in the direction in which the extension shaft member 20 advances, the holding members 50 between each element holder 30 are in a tensioned state. As a result, the plurality of element holders 30 are spaced apart at predetermined intervals.

[0063] According to this embodiment, the following effects are achieved. In this embodiment, the antenna element 40 is wound around the axis of the elongated shaft member 20 on each of the element holders 30 in the stored state, and the direction in which the antenna element 40 is wound around some of the element holders 30 is opposite to the direction in which the antenna element 40 is wound around the remaining parts of the element holders 30. As a result, when the antenna element 40 is deployed while rotating, the moments acting on some of the element holders 30 and the moments acting on the remaining parts of the element holders 30 cancel each other out, so that the moment around the axis of the elongated shaft member 20 as a whole can be reduced and twisting of the entire elongated shaft member 20 can be suppressed. Therefore, twisting can be suppressed when the antenna device 1 is deployed from the stored state to the deployed state.

[0064] Furthermore, according to this embodiment, the directions in which the antenna element 40 is wound around two adjacent element holders 30 are opposite to each other. As a result, when the antenna element 40 is deployed while rotating, the moments acting on the two adjacent element holders 30 cancel each other out, so that the moment around the axis of the extension shaft member 20 as a whole can be reduced, and twisting of the entire extension shaft member 20 can be suppressed. Therefore, the occurrence of twisting during the deployment operation of the antenna device 1 from the stored state to the deployed state can be suppressed.

[0065] Furthermore, according to this embodiment, the direction in which the antenna element 40 is wound around the even-numbered element holders 30 from the base end side of the elongated shaft member 20 among the multiple element holders 30 is opposite to the direction in which the antenna element 40 is wound around the odd-numbered element holders 30. As a result, when the antenna element 40 is deployed while rotating, the moments acting on the even-numbered element holders 30 from the base end side of the elongated shaft member 20 and the moments acting on the odd-numbered element holders 30 cancel each other out, so that the moment around the axis of the elongated shaft member 20 as a whole can be reduced and twisting of the entire elongated shaft member 20 can be suppressed. Therefore, twisting can be suppressed when the antenna device 1 is deployed from the stored state to the deployed state.

[0066] Furthermore, according to this embodiment, the antenna element 40 is formed from convex tape and is wound around the element holder 30 so that the convex surface of the convex tape faces outward in the stored state. This makes it possible to relatively reduce the strain energy stored in the antenna element 40 in the stored state, thereby reducing the moment acting on the element holder 30 when the antenna element 40 rotates and deploys. This makes it possible to suppress twisting when the antenna device 1 is deployed from the stored state to the deployed state.

[0067] Furthermore, according to this embodiment, the direction in which the antenna element 40 is wound around each of the element holders 30 is set so as to minimize the difference between the total strain energy stored in the antenna element 40 wound in one direction around some of the multiple element holders 30 in the stored state and the total strain energy stored in the antenna element 40 wound in the other direction around the remaining parts of the multiple element holders 30. This maximizes the amount by which the moments acting on some of the multiple element holders 30 and the moments acting on the remaining parts of the multiple element holders 30 cancel each other out when the antenna element 40 is deployed while rotating, thereby minimizing the moment around the axis of the extension shaft member 20 as a whole. This therefore makes it possible to suppress the occurrence of twisting when the antenna device 1 is deployed from the stored state to the deployed state.

[0068] Furthermore, according to this embodiment, four antenna elements 40 are connected to each element holder 30 so that the antenna elements 40 extend in a cross shape in the deployed state. This makes it possible to suppress twisting in the antenna device 1 that forms a cross Yagi antenna in the deployed state when the antenna device 1 is deployed from the stored state to the deployed state. [Explanation of symbols]

[0069] 1: Antenna device 10: Housing 10A: Element storage section 10B: Extension shaft member storage section 10C: Power cable storage area 10D: Opening mechanism storage section 11: Housing body 12: Opening and closing lid 13: Spring 14:Open part 15: Hinge 16: Open section drive board 18: Extension shaft member storage device 18A:Shaft part 18B: Connecting member 20: Extension shaft member 20A: Convex tape 30, 30A, 30B, 30C, 30D: Element holder 40: Antenna element 50: Holding member 60: Power supply board 62: Power supply cable 300: Frame 302: Flat plate 304: Opening 310:Protrusion 312: Surface groove 314: Surface convexity 316: Back recess 318:Through hole 324: Wide section 330: First Element Guide 332: Second Element Guide 340: Lid member 342: Wide section 344: Narrow part 346: Through hole 350: Storage unit

Claims

1. An antenna device that can be in a stored state in which it is stored in a housing and in a deployed state in which it extends outward from the housing, an extension shaft member that can be extended in an axial direction from within the housing; a plurality of element holders movable along the extension shaft member; an antenna element deployable from the element holder; Equipped with The antenna element is wound around the axis of the elongated shaft member in each of the element holders in a stored state, a direction in which the antenna element is wound around some of the plurality of element holders is opposite to a direction in which the antenna element is wound around the remaining portions of the plurality of element holders; Antenna device.

2. An antenna device that can be in a stored state in which it is stored in a housing and in a deployed state in which it extends outward from the housing, an elongated shaft member housed within the housing in a state where it is axially retracted relative to the opening of the housing; a plurality of element holders each having an opening and stacked in the housing with the extension shaft member inserted through the opening; a deployable antenna element held by the element holder; Equipped with The antenna element is wound around the axis of the elongated shaft member in each of the element holders in a stored state, a direction in which the antenna element is wound around some of the plurality of element holders is opposite to a direction in which the antenna element is wound around the remaining portions of the plurality of element holders; Antenna device.

3. The directions in which the antenna elements are wound around two adjacent element holders are opposite to each other.

3. The antenna device according to claim 1 or 2.

4. a direction in which the antenna element is wound around an even-numbered element holder from the base end side of the elongated shaft member among the plurality of element holders and a direction in which the antenna element is wound around an odd-numbered element holder are opposite to each other; 3. The antenna device according to claim 1 or 2.

5. The antenna element is formed of a convex tape and is wound around the element holder so that the convex surface of the convex tape faces outward in a stored state.

3. The antenna device according to claim 1 or 2.

6. the direction in which the antenna element is wound around each of the element holders is set so that the difference between the total strain energy stored in the antenna element wound in one direction around some of the plurality of element holders in a stored state and the total strain energy stored in the antenna element wound in the other direction around the remaining portion of the plurality of element holders is minimized.

6. The antenna device according to claim 5.

7. Four antenna elements are connected to each of the element holders so that the antenna elements extend in a cross shape in the deployed state.

3. The antenna device according to claim 1 or 2.

8. An artificial satellite comprising the antenna device according to claim 1 or 2.

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